Restructure pkg/unittest and pkg/webdriver to follow the pub conventions.

tests/html/form_element_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#library('FormElementTest');
+library FormElementTest;
 
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
-#import('dart:html');
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_config.dart';
+import 'dart:html';
 
 void main() {
   useHtmlConfiguration();
 
   var isFormElement = predicate((x) => x is FormElement, 'is a FormElement');
 
   test('constructorTest1', () {
     var form = new FormElement();
     expect(form, isNotNull);
     expect(form, isFormElement);
@@ skipping 56 matching lines @@
     form.noValidate = true;
     expect(form.noValidate, true);
   });
   
   test('targetTest', () {
     var target = 'target';
     form.target = target;
     expect(form.target, target);
   });
 }